The present invention relates to an air cleaner that is employed in a fuel cell system and arranged in a passage for supplying air to a fuel cell main body.
A fuel cell system includes a passage for supplying fuel gas to the fuel cell main body having an electrolyte membrane and a passage for supplying oxidation gas to the fuel cell main body.
For example, in a vehicle equipped with a fuel cell system, that is, in a vehicle that travels with electric power generated by the fuel cell main body as a power source, air outside the vehicle containing oxidation gas is drawn in by a compressor. The drawn-in air is supplied to the fuel cell main body through an air supply passage (see, for example, Japanese Laid-Open Patent Publication No. 2008-52969).
In the air supply passage described in the publication, an air cleaner and the compressor are provided in the order from the upstream side. The air cleaner has in its case an air filter made of filter paper. When the air drawn-in from outside the vehicle passes through the air filter, the dust contained in the air is removed by the air filter.
Air contains impure gases such as sulfur dioxide and hydrogen sulfide. In particular, when such sulfur-based gas flows into the fuel cell main body and is adsorbed by a platinum catalyst or the like, the catalytic function may be degraded so that the battery performance is reduced. In this regard, it has been conventionally proposed to provide an adsorption filter for adsorbing impure gas in the middle of the air supply passage.
Conventional air cleaners for fuel cell systems including the air cleaner described in the publication still have room for improvement in dust removal performance. Also, providing a filter for collecting dust and a filter for adsorbing impure gas in the air supply passage increases the airflow resistance, increasing the pressure loss. Furthermore, providing a filter for collecting dust contained in the air and a filter for adsorbing impure gas complicates the structure of the air supply passage.